There are high expectations for reflective displays, such as e-paper, cholesteric displays, and interferometric modulation displays, as the next generation of displays having the characteristics of low power consumption and an excellent reflective constant ratio. Such reflective displays require a light guide structure to emit white light toward their display panel, but conventional light guide structures, such as those using a mirror to irradiate white light toward a display panel from a front edge thereof, or those configured to provide white light toward a display panel from a side edge thereof, are unsuitable for reflective displays having a large display area, because it is difficult to obtain a uniform light intensity distribution throughout such a large display area by using such conventional light guide structures. Therefore, a demand exists for light guide structures capable of emitting white light having a uniform light intensity distribution throughout a large display area.